package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private IFollowService followService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;


    /**
     * 根据博客id查询博客内容信息
     * @param id
     * @return
     */
    @Override
    public Result queryBlogById(Long id) {
        //1、查询blog
        Blog blog = getById(id);
        if (blog == null){
            return Result.fail("博客笔记不存在");
        }
        //2、blog有关的用户
        queryBlogUser(blog);
        //3. 查询blog是否被点赞
        isBolgLiked(blog);
        return Result.ok(blog);
    }
    //查询是否被点赞
    private void isBolgLiked(Blog blog) {
        //1、获取当前用户
        UserDTO user = UserHolder.getUser();
        if (user == null){
            //用户未登录无需查询是否点赞
            return;
        }
        Long userId = UserHolder.getUser().getId();
        //2、判断是否点赞
        String key = "blog:liked:" + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBolgLiked(blog);
        });
        return Result.ok(records);
    }

    /**
     * 博文点赞
     * @param id
     * @return
     */
    @Override
    public Result likeBlog(Long id) {
        //1、获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2、判断是否点赞
        String key = BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score == null) {
            //3、如果未点赞，可以点赞
            //3.1 数据库点赞+1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2 保存用户到redis的set集合  zadd  key，value(用户id)，score(时间戳)
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key, userId.toString(),System.currentTimeMillis());
            }
        }else {
            //4. 如果已经点赞，取消点赞
            //4.1 数据库点赞-1
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            //4.2 把用户点赞从redis中set移除
            if (isSuccess){
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return null;
    }

    /**
     * 根据博客查用户id
     * @param id
     * @return
     */
    @Override
    public Result queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        //1. 查询top5的点赞用户 zrage key 0 4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //2. 解析出用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        //3. 更具用户id查询用户
        List<UserDTO> userDTOS = userService.query()
                .in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4. 返回
        return Result.ok(userDTOS);
    }

    /**
     * 保存探店笔记（后发送给粉丝）
     * @param blog
     * @return
     */
    @Override
    public Result saveBlog(Blog blog) {
        //1. 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2. 保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败！");
        }
        //3. 查询笔记作者所有粉丝 select * from tb_follow where follow_user_id = ？
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        //4. 推送笔记给粉丝
        for (Follow follow : follows){
            //4.1.获取粉丝id
            Long userId = follow.getId();
            //4.2.推送  soutSet
            String key = FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        //5. 返回id
        return Result.ok(blog.getId());
    }
    /**
     * 推送blog消息
     * @param max
     * @param offset
     * @return
     */
    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //1. 获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2. 查询收件箱
        String key = FEED_KEY + userId;
        //3. 解析数据 ：blogId、minTime（最小时间搓） offset
        
        //4. 根据id查询blog
        //5. 封装返回
        return null;
    }
}
